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author | Sebastian Schmelzer | 2010-10-25 16:53:54 +0200 |
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committer | Sebastian Schmelzer | 2010-10-25 16:53:54 +0200 |
commit | 3050a9253437f4a4b5ad4bf3b3efdc3c660a5137 (patch) | |
tree | 91ac22153e416aac7ca20916b314b5e2ffa871b1 /contrib/syslinux-4.02/com32/lua/etc/strict.lua | |
download | preboot-3050a9253437f4a4b5ad4bf3b3efdc3c660a5137.tar.gz preboot-3050a9253437f4a4b5ad4bf3b3efdc3c660a5137.tar.xz preboot-3050a9253437f4a4b5ad4bf3b3efdc3c660a5137.zip |
Diffstat (limited to 'contrib/syslinux-4.02/com32/lua/etc/strict.lua')
-rw-r--r-- | contrib/syslinux-4.02/com32/lua/etc/strict.lua | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/contrib/syslinux-4.02/com32/lua/etc/strict.lua b/contrib/syslinux-4.02/com32/lua/etc/strict.lua new file mode 100644 index 0000000..604619d --- /dev/null +++ b/contrib/syslinux-4.02/com32/lua/etc/strict.lua @@ -0,0 +1,41 @@ +-- +-- strict.lua +-- checks uses of undeclared global variables +-- All global variables must be 'declared' through a regular assignment +-- (even assigning nil will do) in a main chunk before being used +-- anywhere or assigned to inside a function. +-- + +local getinfo, error, rawset, rawget = debug.getinfo, error, rawset, rawget + +local mt = getmetatable(_G) +if mt == nil then + mt = {} + setmetatable(_G, mt) +end + +mt.__declared = {} + +local function what () + local d = getinfo(3, "S") + return d and d.what or "C" +end + +mt.__newindex = function (t, n, v) + if not mt.__declared[n] then + local w = what() + if w ~= "main" and w ~= "C" then + error("assign to undeclared variable '"..n.."'", 2) + end + mt.__declared[n] = true + end + rawset(t, n, v) +end + +mt.__index = function (t, n) + if not mt.__declared[n] and what() ~= "C" then + error("variable '"..n.."' is not declared", 2) + end + return rawget(t, n) +end + |